Clear water gushes from a hole in the ground, forming Bonanza Spring, the largest spring in the southeastern Mojave Desert.

This rare oasis is at the center of the fight over a company’s plan to pump groundwater and sell it to California cities.

Cadiz Inc. is proposing to pump an average of 16.3 billion gallons of water each year for 50 years. The company says the project won’t harm any of the springs in the area, and it recently presented a study in which researchers concluded Bonanza Spring wouldn’t be affected by its groundwater pumping.

Now other researchers have come to the opposite conclusion, saying in a new study that Bonanza Spring is likely connected to the same aquifer where the company plans to draw water from wells, and that the project would put the spring at risk of drying up.

Andy Zdon, a hydrogeologist who led the study, analyzed water samples from the spring and determined that unlike other nearby springs, which are fed by rainfall that collects in relatively shallow underground sources, Bonanza Spring flows with water that comes from much deeper underground.

Zdon said the research points to a “hydraulic connection” between the spring and the aquifer that Cadiz intends to use, indicating the spring would probably be affected by the decline in the water table.

“The spring is going to be highly susceptible to drawdown from the pumping,” Zdon said. “It would likely dry up.”

The study, which was published Friday in the journal Environmental Forensics, involved a chemical analysis of water from Bonanza Spring and other springs in Mojave Trails National Monument. The research was conducted by consulting firm Partner Engineering and Science Inc. and funded by the Mojave Desert Land Trust, a nonprofit conservation group that opposes the Cadiz project.

Zdon and his team analyzed the oxygen and hydrogen isotopes in the water and said the water in Bonanza Spring has different characteristics than several other springs in this part of the desert. The stable isotopes in rainwater vary with latitude and elevation, and Zdon and his colleagues used those “signatures” to examine the sources of the spring water.

They determined that Hummingbird, Teresa, and Chuckwalla Springs are “perched” springs, which are relatively shallow and fed by local rainfall percolating into the ground, but that the water in Bonanza Spring differs from local rainfall and instead matches rain that falls well north of the Clipper Mountains in other mountains in the Mojave National Preserve.

The scientists also found that unlike other springs, the water in Bonanza Spring has similar characteristics to groundwater in the aquifer in the adjacent Fenner Valley — including the Fenner Gap, an area where Cadiz plans to pump groundwater.

Zdon coauthored the research with hydrogeologists M. Lee Davisson and Adam H. Love. They said in the study that Bonanza Spring “has generally been assumed to be a perched spring disconnected from the basin-fill aquifer system,” but that their results indicate it’s likely connected with that larger reserve of groundwater.

And if groundwater levels decline due to pumping, the researchers wrote, that “could result in an uncertain, but potentially substantial decrease in free-flowing water from the spring.”

Cadiz disputed the findings, and scientists who recently studied the spring for the company called the new research flawed.

“Zdon does not account for the existence of two observable geologic faults that fully insulate the Bonanza Spring from any impact from the Cadiz Water Project,” Cadiz President and CEO Scott Slater said in a statement.

In the earlier study commissioned by the Los Angeles-based company, researchers identified two faults that they said block groundwater flowing in fractured bedrock. They said those two “bounding faults” intersect at the spring, and groundwater spills over the faults to form the spring.

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Bonanza Spring flows at a rate of about 10 gallons a minute, sustaining an oasis in the Clipper Mountains.(Photo: Jay Calderon/The Desert Sun)

The study, which was released in January, was conducted by geologist Miles Kenney and hydrogeologist Terry Foreman, who said the effects of groundwater drawdown around the company’s wells wouldn’t reach the area of the spring due to a “hydraulic disconnect” and faults between the two areas.

The wellfield where the company intends to pump groundwater is located about 1,000 feet lower in elevation than the spring, and about 11 miles away.

In their assessment, Kenney and Foreman wrote that “the spring’s discharge is localized within a fractured rock system that is hydraulically separated from the alluvial regional groundwater system in Fenner Valley located three miles to the east.” They said their research “demonstrates that the perennial spring discharge is controlled by the existence of two bounding faults.”

As part of the research, Kenney mapped the faults and the geology around the spring. During six days of field work, Kenney inspected a tunnel uphill from the spring on the mountainside that was apparently excavated in the early 1900s by miners, and he found a portion of the fault exposed in the wall of the passage. The other intersecting fault zone was also visible.

“Essentially those faults act like dams,” Foreman said. “It’s effectively a subsurface dam that then causes the water to overspill, groundwater to spill over those faults.”

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Water comes out of a hole in the ground and forms Bonanza Spring, the largest spring in the southeastern Mojave Desert.(Photo: Jay Calderon/The Desert Sun)

The researchers who prepared the study for Cadiz said the spring’s flow depends on recharge from precipitation in a catchment area that extends over four miles to the north.

“The spring is going to be controlled absolutely by climatic conditions, basically changes in long-term rainfall and recharge above where those faults occur,” Foreman said. “It’s going to be driven by that recharge as opposed to anything that happens in the valley.”

Arguing over the science

Zdon said he disagreed with the conclusions of the study commissioned by Cadiz. He pointed out that Kenney and Foreman didn’t include a similar analysis of water samples.

“You can’t begin to source where water comes from without looking at the water itself, and they did not do that,” Zdon said.

Zdon previously conducted a survey of more than 300 springs and water holes across the Mojave Desert for the federal Bureau of Land Management during 2015 and 2016. He’s found that most of the springs in the desert rely on local precipitation and may increase or decrease in flow depending on whether it’s been wet or dry.

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Researcher Andy Zdon takes notes on the vegetation and birds while surveying a spring in the Amargosa River Basin near Death Valley in 2016.(Photo: Marilyn Chung/The Desert Sun)

But Zdon said records from more than a century ago show that Bonanza Spring is different and that its flow has held steady at about 10 gallons a minute. It’s still putting out as much water as it did in the early 1900s, he said, when a pipeline carried water downhill to the railway stop in Danby to fill tanks aboard passing steam engines.

Zdon said other measurements provided additional clues. When a spring depends on shallow groundwater, the water temperature is usually close to the average annual air temperature. But the water in Bonanza Spring emerges from the ground more than 11 degrees warmer, indicating it’s warmed up by the earth deep underground. His team calculated the water must be coming up from more than 750 feet underground.

Zdon also analyzed the water to check for tritium, a radioactive isotope of hydrogen that was released into the atmosphere with nuclear weapons testing starting in the late 1940s. The water in nearby Teresa Spring contains tritium, showing the water fell as rain or snow sometime between the 40s and the present day. But the water in Bonanza Spring contains no tritium, indicating it’s been underground since before those atomic tests.

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Dozens of species of plants grow at Bonanza Spring in the Mojave Desert.(Photo: Jay Calderon/The Desert Sun)

Zdon said other carbon-dating tests, which weren’t described in their study, have found that the water coming out of Bonanza Spring has been underground for approximately 15,000 years.

“So, between the groundwater ages, the temperatures and the chemistry, looking at it from three different directions, it’s all pointing to the same answer: that this is tied into more regional flow,” Zdon said. “That water has got to be moving towards the Clipper Mountains through the basin-fill aquifer… and seeping through the Clipper Mountains, probably along fractured rocks along the fault zones, and surfacing at the spring.”

On that point, too, the scientists who prepared the report for Cadiz said they disagree based on their observations and their work mapping the faults and reviewing scientific papers. They also studied documents concerning two old mines located about a mile northeast of the spring.

The groundwater levels in those inactive mines are about 150 feet lower than the elevation where water flows from Bonanza Spring, they wrote, suggesting that the faults in the area, which run from the northwest toward the southeast, act as barriers and “groundwater flow is effectively compartmentalized.”

“It’s physically impossible for groundwater to move from the north, across that area where those mines are, to Bonanza Spring,” Foreman said. “Groundwater levels to the north of Bonanza Spring are lower, so there’s no way that groundwater levels can go from a high to a low and then essentially go back uphill. It’s just physically not possible.”

Kenney also reviewed aerial images in mapping the faults and the geology. Cadiz’s research team said they found other geologic signs including an abundance of precipitated minerals along the fault zones, “indicating that the faults can be strong groundwater barriers.”

As part of the study commissioned by Cadiz, 10 hydrologists and geologists visited the spring in December with Foreman and Kenney, and five of them reviewed the report and agreed with the conclusion that the spring wouldn’t be affected by the water project.

Cadiz has proposed to pump groundwater on land surrounded by Mojave Trails National Monument. The company owns 34,000 acres in the desert along Route 66, and it plans to build a 43-mile pipeline to carry water from its property to the Colorado River Aqueduct.

In 2011 and 2012, Cadiz’s proposal went through an environmental review under the California Environmental Quality Act. Orange County’s Santa Margarita Water District served as the lead agency in the review process and certified the environmental impact report. The document repeatedly states that “the physical evidence indicates” the aquifer isn’t connected to the springs and therefore the pumping would have no impact on the springs.

Conservation groups challenged the environmental review in court, but they lost.

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The setting sun lights up the sky over Bonanza Spring in the Mojave Desert.(Photo: Jay Calderon/The Desert Sun)

Frazier Haney, land conservation director for the Mojave Desert Land Trust, said the new research shows those environmental review documents were based on incomplete science and that the water project poses a serious threat to the spring.

During a visit to Bonanza Spring, Haney walked past blooming brittlebush shrubs and wildflowers to the edge of the spring, where the thick vegetation rustled in the breeze. He said he’s seen mountain lion tracks here. The spring is also frequented by bighorn sheep and bobcats that come to drink, and by migratory birds that forage among the trees.

Frogs and tadpoles swim in the ponds, and dozens of species of native plants grow in the wetland, which stretches a half-mile downhill from the spot where water pours out of the ground.

Walking to the top of a bluff, Haney looked out over the springs.

“It’s a magical place,” Haney said. “Springs like this are one of the most important parts of the ecosystem.”

From the ridges above the spring, you can see the open desert of the Fenner Valley below. It stretches out in a plain between mountain ranges, covered with creosote bushes. Haney pointed out the patch of the desert where Cadiz is proposing to drill new wells.

“Intensive groundwater pumping out here could be devastating for the ecosystem,” Haney said.

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Researchers recently prepared a study for Cadiz Inc. in which they concluded the company's water project wouldn't harm Bonanza Spring, which is located 11 miles from an area where groundwater would be pumped.(Photo: Jay Calderon/The Desert Sun)

His group focuses on buying lands to protect parts of the desert for conservation. It has purchased more than 71,000 acres for conservation since 2006. Some of those lands have been transferred to the federal government and have become part of the Mojave Trails National Monument.

Cadiz’s managers have said they plan to use groundwater that would otherwise gradually flow downhill and evaporate from two dry lakes. On those dry lakebeds, other companies dig trenches in the cracked soil to extract salts left by the evaporating water.

The concept of using water that would otherwise evaporate from the lakebeds is reflected in the company’s formal name for its plan: the Cadiz Valley Water Conservation, Recovery and Storage Project.

“The Cadiz Water Project will stop the annual loss of more than 10 billion gallons per year to evaporation,” Courtney Degener, a vice president and spokesperson for the company, said in an email. “It cannot and will not impact area springs but it will make available new water for 400,000 people, create critical groundwater storage capacity for our region and support 5,900 new jobs in a safe and sustainable way.”

Degener said Zdon’s new study “fails to account for the most current field work and hydrogeological conclusions about area springs, and does not present any new credible findings.”

‘Cone of depression’

Cadiz’s proposal has been hotly debated for years. While pursuing the plan to sell water, the company has been pumping groundwater on its property to irrigate nearly 2,000 acres of farmland, growing lemons, grapes, raisins and other crops.

During President Barack Obama’s administration, federal officials had hindered the project by ruling that the company would need a new permit to build a water pipeline alongside a railroad.

But in October, President Donald Trump’s administration reversed that decision and gave the company a green light. The federal Bureau of Land Management told Cadiz it wouldn’t need a permit to build the pipeline along the railroad right-of-way.

Two environmental groups — the Center for Biological Diversity and the Center for Food Safety — are challenging that decision in a lawsuit. Another group, the National Parks Conservation Association, is suing to challenge a related policy change: a 2017 Interior Department legal opinion that said railroad companies are allowed to lease out portions of their rights-of-way for other purposes without going through a federal environmental review.

Cadiz has said it plans to move ahead with designing and building the water pipeline alongside the railroad.

That plan still could face obstacles, though, because some of the land where Cadiz wants to build the pipeline is owned by the state. And in September, California’s State Lands Commission told the company that any use of the state-owned lands under its jurisdiction would require a lease and its approval.

Opponents of the project seized on the new study, saying it reveals problems in the 2012 environmental review.

“Given this new information, I strongly believe Cadiz’s CEQA review must be reexamined,” Sen. Dianne Feinstein said in a statement Friday. “Cadiz needs to accept this new scientific study and abandon its goal of draining the Mojave Desert of its most precious resource: water. It’s time Cadiz and its investors give up on this desert boondoggle.”

Chris Clarke, California desert program manager for the National Parks Conservation Association, agreed and said the new research “demonstrates Cadiz has used a flawed hydrology model that produced flawed analysis” for the environmental review. He said that process “now must be corrected through additional environmental review.”

The company’s officials have defended the environmental review, pointing out that California’s environmental law is considered more stringent than any federal environmental law and that San Bernardino County in 2012 approved a groundwater management plan — formally titled the Groundwater Management, Monitoring and Mitigation Plan — which sets additional limits for the project.

Cadiz also points to the court decisions upholding the review.

“Peer-reviewed science, physical observations of the region and California’s courts all agree: The Cadiz Water Project will protect the desert environment including Bonanza Spring,” Degener said.

The groundwater management plan details the county’s oversight role for the project.

“It is not anticipated that the Project will have any impact on the springs,” the document says. “Nonetheless, this Management Plan provides for quarterly monitoring of the Bonanza Spring as an ‘indicator spring’ because it is the spring that is in closest proximity to the Project wellfield.”

The plan calls for “baseline and periodic visual observation and flow estimates” and says monitoring wells between the wellfield and the spring would be used to track groundwater levels.

According to the plan, if there’s a reduction in the spring’s flow and it’s determined to be due to the company’s wells, “corrective measures” would include reducing pumping, changing pumping locations in the wellfield or stopping groundwater extraction.

One of the concerns that Zdon and others raise about Cadiz’s plan is that the pumping would create a “cone of depression” in the aquifer as groundwater flows from surrounding areas toward the company’s wellfield.

The way groundwater drawdown occurs in the desert, Zdon said, “it’s very hard to control what happens once that cone of depression starts building.”

Once the pumping begins to lower the water table, that depressed area of the aquifer would continue to expand for years, even if the pumping were stopped.

Given that dynamic, Zdon said, the monitoring plan “is not sufficient to be protective of the spring.”

“When you lower the water table below a spring system like that, the first thing you would notice is a reduction in surface flow and maybe a complete cessation of any kind of surface water at the site,” Zdon said. “If you see an impact at the spring, it’s probably too late.”

Cadiz’s executives and researchers responded that the sort of monitoring Zdon is calling for is already part of the county’s plan.

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Degener said the project “will be regulated by an extensive groundwater monitoring plan enforced by the County that includes the exact kind of groundwater monitoring Zdon recommends and goes even further including monitoring features across the entire watershed.”

There are already two existing monitoring wells, one uphill from Fenner Valley and another close to Danby, Foreman said.

“It’s interesting that the water temperature in those wells is actually higher than the water temperature of the spring,” Foreman said. “And so that water has obviously moved over long distances and it’s 2 to 3 degrees higher in temperature than the spring, so we think that the spring is more local water, and those water temperatures show that separation.”

Kenney and Foreman said some of Zdon’s findings are consistent with their own but they disagree with the conclusions, including that the spring would be fed by recharge from an area far to the north.

“I’m wondering how much of his findings might change if he was to consider the watershed that we considered, not north of the Clippers but just simply the rocks in the western Clipper Mountains,” Kenney said.

Zdon and his colleagues stressed that if the pumping begins, more intensive monitoring would be necessary to protect the spring. They wrote that the groundwater monitoring “should be designed to obtain sufficient early warning of potentially damaging groundwater level decline.”

They said relying on observable changes at the spring would be ineffective, and that drilling monitoring wells close to Bonanza Spring would provide a way of spotting a decline quickly — before it’s too late for the spring.

Their research included not only data collected by Zdon and his colleagues, but also data from a study that researchers from the Lawrence Livermore National Laboratory conducted in 2000 for Cadiz and the Metropolitan Water District, which were working together at the time on an earlier iteration of the project.

That earlier research focused on identifying the recharge area and estimating the amount of recharge. It included geochemical analyses of the water in Bonanza Spring and other springs and wells.

Davisson, who was one of Zdon’s coauthors, also helped carry out that research for Lawrence Livermore back in 2000, and the data was publicly released in August 2017.

Zdon said the data helped confirm his team’s findings.

“We were actually largely using the same analytical techniques in sampling that Lawrence Livermore used back in 2000 on behalf of Cadiz,” Zdon said. “What that did was essentially confirm our sampling, because basically our results 17 years later were nearly identical with what Lawrence Livermore came up with.”